Hi,
On Wed, Oct 09, 2013 at 05:43:17PM +0800, Chen Fan wrote:
> When OS eject a vcpu (like: echo 1 > /sys/bus/acpi/devices/LNXCPUXX/eject),
> it will call acpi EJ0 method, the firmware will write the new cpumap, QEMU
> will know which vcpu need to be ejected.
I think that the _EJ0 callback (CPEJ method in
hw/i386/acpi-dsdt-cpu-hotplug.dsl)
currently does not write the new cpumap, it only sleeps. So cpu_state_write is
never called on ejection, and the cpu objects remain allocated in qemu. Is there
an updated version of the patchseries with a CPEJ that writes the new cpumap?
thanks,
- Vasilis
>
> Signed-off-by: Chen Fan <chen.fan.f...@cn.fujitsu.com>
> ---
> hw/acpi/piix4.c | 37 ++++++++++++++++++++++++++++++++++++-
> 1 file changed, 36 insertions(+), 1 deletion(-)
>
> diff --git a/hw/acpi/piix4.c b/hw/acpi/piix4.c
> index dc506bf..fd27001 100644
> --- a/hw/acpi/piix4.c
> +++ b/hw/acpi/piix4.c
> @@ -61,6 +61,7 @@ struct pci_status {
>
> typedef struct CPUStatus {
> uint8_t sts[PIIX4_PROC_LEN];
> + uint8_t old_sts[PIIX4_PROC_LEN];
> } CPUStatus;
>
> typedef struct PIIX4PMState {
> @@ -611,6 +612,12 @@ static const MemoryRegionOps piix4_pci_ops = {
> },
> };
>
> +static void acpi_piix_eject_vcpu(int64_t cpuid)
> +{
> + /* TODO: eject a vcpu, release allocated vcpu and exit the vcpu pthread.
> */
> + PIIX4_DPRINTF("vcpu: %" PRIu64 " need to be ejected.\n", cpuid);
> +}
> +
> static uint64_t cpu_status_read(void *opaque, hwaddr addr, unsigned int size)
> {
> PIIX4PMState *s = opaque;
> @@ -623,7 +630,27 @@ static uint64_t cpu_status_read(void *opaque, hwaddr
> addr, unsigned int size)
> static void cpu_status_write(void *opaque, hwaddr addr, uint64_t data,
> unsigned int size)
> {
> - /* TODO: implement VCPU removal on guest signal that CPU can be removed
> */
> + PIIX4PMState *s = opaque;
> + CPUStatus *cpus = &s->gpe_cpu;
> + uint8_t val;
> + int i;
> + int64_t cpuid = 0;
> +
> + val = cpus->old_sts[addr] ^ data;
> +
> + if (val == 0) {
> + return;
> + }
> +
> + for (i = 0; i < 8; i++) {
> + if (val & 1 << i) {
> + cpuid = 8 * addr + i;
> + }
> + }
> +
> + if (cpuid != 0) {
> + acpi_piix_eject_vcpu(cpuid);
> + }
> }
>
> static const MemoryRegionOps cpu_hotplug_ops = {
> @@ -643,13 +670,20 @@ static void piix4_cpu_hotplug_req(PIIX4PMState *s,
> CPUState *cpu,
> ACPIGPE *gpe = &s->ar.gpe;
> CPUClass *k = CPU_GET_CLASS(cpu);
> int64_t cpu_id;
> + int i;
>
> assert(s != NULL);
>
> *gpe->sts = *gpe->sts | PIIX4_CPU_HOTPLUG_STATUS;
> cpu_id = k->get_arch_id(CPU(cpu));
> +
> + for (i = 0; i < PIIX4_PROC_LEN; i++) {
> + g->old_sts[i] = g->sts[i];
> + }
> +
> if (action == PLUG) {
> g->sts[cpu_id / 8] |= (1 << (cpu_id % 8));
> + g->old_sts[cpu_id / 8] |= (1 << (cpu_id % 8));
> } else {
> g->sts[cpu_id / 8] &= ~(1 << (cpu_id % 8));
> }
> @@ -688,6 +722,7 @@ static void piix4_acpi_system_hot_add_init(MemoryRegion
> *parent,
>
> g_assert((id / 8) < PIIX4_PROC_LEN);
> s->gpe_cpu.sts[id / 8] |= (1 << (id % 8));
> + s->gpe_cpu.old_sts[id / 8] |= (1 << (id % 8));
> }
> memory_region_init_io(&s->io_cpu, OBJECT(s), &cpu_hotplug_ops, s,
> "acpi-cpu-hotplug", PIIX4_PROC_LEN);
> --
> 1.8.1.4
>
>
